Heat exchanger having a plurality of heat exchange tubes

ABSTRACT

A heat exchanger is provided which may include a first heat exchange tube in a pipe shape, including a first fluid inlet, into which a first fluid may be introduced and flow, and a first fluid outlet, through which the first fluid may be discharged; a second heat exchange tube that passes through the first heat exchange tube, including a second fluid inlet, into which a second fluid may be introduced and flow, and a second fluid outlet, through which the second fluid may be discharged; and a third heat exchange tube that includes a third fluid inlet, into which the second fluid discharged through the second fluid outlet may be introduced and flow, and a third fluid outlet, through which the second fluid may be discharged, the third fluid outlet enclosing an external surface of the first heat exchange tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of prior U.S. patentapplication Ser. No. 12/987,410 filed Jan. 10, 2011, which claimspriority under 35 U.S.C. §119 to Korean Application No. 10-2010-0002865,filed in Korea on Jan. 12, 2010, whose entire disclosure is herebyincorporated by reference.

BACKGROUND

1. Field

A heat exchanger is disclosed herein.

2. Background

Heat exchangers are known. However, they suffer from variousdisadvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described in detail with reference to the followingdrawings in which like reference numerals refer to like elements, andwherein:

FIG. 1 is a perspective view of a heat exchanger according to anembodiment;

FIG. 2 is a cross sectional view of the heat exchanger of FIG. 1, takenalong line II-II;

FIG. 3 is a longitudinal-sectional view of the heat exchanger of FIG. 1,taken along line III-III of FIG. 1;

FIG. 4 is a sectional view of a heat exchanger according to anotherembodiment;

FIG. 5 is a sectional view of a heat exchanger according to anotherembodiment;

FIG. 6 is a perspective view of a heat exchanger according to anotherembodiment;

FIG. 7 is a sectional view of the heat exchanger of FIG. 6; and

FIG. 8 is a sectional view of a heat exchanger according to anotherembodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described with reference to theaccompanying drawings. In this disclosure, the size and shape ofcomponents shown in the drawings may be exaggerated for the sake ofclarity and convenience. Further, terms that are specifically defined inconsideration of construction and operation of the disclosed embodimentsmay be changed according to an operator's intention or custom.Definition of such items should be made on the basis of the entirecontents of this disclosure.

A heat exchanger is an apparatus that reduces a temperature of a hightemperature fluid and increases a temperature of a low temperature fluidby transferring thermal energy from the high temperature fluid to therelatively low temperature fluid. Such a heat exchanger may be utilizedin, for example, a heater, a cooler, an evaporator, or a condenser.

In such a heat exchanger, a heat transfer medium used to transfer heatto a fluid to be heated may be referred to as a heat medium, and a heattransfer medium used to take heat from a fluid may be referred to as arefrigerant. The heat medium or refrigerant may be, for example, air ora liquid.

A double-pipe heat exchanger is a heat exchanger that includes aninternal tube, through which a first fluid may be introduced or pass,and an external tube, which encloses the internal pipe and through whicha second fluid may be introduced or pass. Heat exchange may be performedbetween the fluids using a side wall of the internal tube as a heattransfer wall.

The double-pipe heat exchanger may have a low heat exchange efficiency,because a heat transfer area where an external wall of the internal tubeand a second fluid contact each other may be small. Therefore, in orderto increase the heat transfer efficiency, a size of the double-pipe heatexchanger must be enlarged or a length of the double-pipe elongated.However, due to the increased volume of the double-pipe heat exchanger,it may be difficult to elongate the length of the double-pipe heatexchanger or enlarge the size of the double-pipe heat exchanger.

FIG. 1 is a perspective view of a heat exchanger according to anembodiment. FIG. 2 is a cross-sectional view of the heat exchanger ofFIG. 1, taken along line II-II of FIG. 1. FIG. 3 is alongitudinal-sectional view of the heat exchanger of FIG. 1, taken alongline of FIG. 1.

Referring to FIGS. 1 to 3, a heat exchanger 800 may include a first heatexchange tube 100, a second heat exchange tube 200, and a third heatexchange tube 300. In addition, the heat exchanger 800 may include aconnection tube 400 that connects the second and third heat exchangetubes 200 and 300.

The first heat exchange tube 100 may be a tube into which a first fluidmay be introduced and flow. The first heat exchange tube 100 may includean upper wall 103, a lower wall 104, and a side wall 108 disposedbetween the upper and lower walls and connecting them. Further, thefirst heat exchange tube 100 may be formed in a pipe shape.

An upper portion of the side wall 108 of the first heat exchange tube100 may be connected to a first fluid inlet 102, into which the firstfluid may be introduced and flow, and a lower portion of the side wall108 of the first heat exchange tube 100 facing the upper portion of theside wall may be connected to a first fluid outlet 105, through whichthe first fluid may be discharged.

The first fluid may be introduced through the first fluid inlet 102 ofthe first heat exchange tube 100 and discharged through the first fluidoutlet 105. In this embodiment, the first fluid may have a firsttemperature.

The second heat exchange tube 200 may be provided with a second fluidwhose temperature is different from that of the first fluid. A diameterof the second heat exchange tube 200 may be formed to be smaller than adiameter of the first heat exchange tube 100, and the second heatexchange tube 200 may pass through the first heat exchange tube 100 in alongitudinal direction. Referring to FIG. 3, the second heat exchangetube 200 may be disposed at a center of the first heat exchange tube 100so that their axes are concentric.

A second fluid inlet 202, into which the second fluid may be introducedand flow, may be formed at one end of the second heat exchange tube 200,and a second fluid outlet 205 may be formed at the other end of thesecond heat exchange tube 200, the second fluid outlet 205 dischargingthe second fluid to a connection tube 400 described hereinbelow. Thesecond fluid introduced into the second heat exchange tube 200 throughthe second fluid inlet 202 may have a second temperature lower than thefirst temperature of the first fluid.

The second heat exchange tube 200 may be a straight tube, that is,formed in a straight line shape in the first heat exchange tube 100.Side walls 108, 208 of the first heat exchange tube 100 and the secondheat exchange tube 200 may be used as heat transfer walls, through whichheat exchange may be performed between the first and second fluids.

The second fluid, which flows through the second heat exchange tube 200and connection tube 400, may flow into the third heat exchange tube 300.A diameter of the third heat exchange tube 300 may be greater than adiameter of the first heat exchange tube 100 and may be disposed outsideof the first heat exchange tube 100 to enclose a side wall 108 of thefirst heat exchange tube 100.

Referring to FIG. 3, the third heat exchange tube 300 may be disposed sothat axes of the first heat exchange tube 100 and the third heatexchange tube 300 are concentric. The third heat exchange tube 300 mayhave an upper wall 303, a lower wall 304, and a side wall 308 disposedbetween the upper and lower walls 303, 304 and connecting them. The sidewall 308 may be formed in a cylindrical shape. A third fluid inlet 302,into which the second fluid which has passed through the second heatexchange tube 200 may flow, may be formed on the lower wall 304 of thethird heat exchange tube 300, and a third fluid outlet 305, throughwhich the second fluid may be discharged, may project from the side wall308 on an upper portion of the third heat exchange tube 300.

Centers of the upper and lower walls 303, 304 may be open, so that thefirst heat exchange tube 100 may be inserted therethrough. Further, anempty space whose diameter is greater than that of the first heatexchange tube 100 may be formed in the third heat exchange tube 300.

Because the second fluid when it flows into the third heat exchange tube300 is in the state in which its heat has been primarily exchanged withthat of the first fluid while in the second heat exchange tube 200, atemperature of the second fluid may be slightly higher than that of thesecond fluid when it flows into the second heat exchange tube 200.

The second and third heat exchange tubes 200 and 300 may be formed asone body. Alternatively, the second and third heat exchange tubes 200and 300 may communicate with each other via the connection tube 400.

The connection tube 400 may connect the second and third heat exchangetubes 200 and 300 so that the second fluid having passed through thesecond heat exchange tube 200 may flow into the third heat exchange tube300. That is, one end of the connection tube 400 may communicate withthe second fluid outlet 205 of the second heat exchange tube 200, andthe other end of the connection tube 400 may communicate with a thirdfluid inlet 302 of the third heat exchange tube 300.

FIG. 4 is a sectional view of a heat exchanger according to anotherembodiment. The heat exchanger 800A shown in FIG. 4 has substantiallythe same construction as the heat exchanger shown in FIG. 3, except forthe second heat exchange tube. Accordingly, like reference members havebeen used to indicate like elements, and repetitive disclosure omitted.

Referring to FIG. 4, in the heat exchanger 800A, the second heatexchange tube 220 disposed in the first heat exchange tube 100 mayinclude a bent tube, which may be bent at least once in the first heatexchange tube 100.

FIG. 5 is a sectional view of a heat exchanger according to anotherembodiment. The heat exchanger 800B shown in FIG. 5 has substantiallythe same construction as the heat exchanger shown in FIG. 3, except forthe second heat exchange tube. Accordingly, like reference members havebeen used to indicate like elements, and repetitive disclosure omitted.

Referring to FIG. 5, in the heat exchanger 800B, the second heatexchange tube 230 disposed in the first heat exchange tube 100 mayinclude a curved tube having at least one curve, which is curved at apredetermined curvature, in the first heat exchange tube 100.

FIG. 6 is a perspective view of a heat exchanger according to anotherembodiment. FIG. 7 is a sectional view of the heat exchanger of FIG. 6.Referring to FIGS. 6 and 7, the heat exchanger 800C may include a hightemperature heat exchange tube 500 and a low temperature heat exchangetube 600.

The high temperature heat exchange tube 500 may be a tube into which afirst fluid, being the target fluid, may be introduced and flow. Thehigh temperature heat exchange tube 500 may include an upper wall 503, alower wall 504, and a side wall 508 disposed between the upper and lowerwalls 503, 504 and connecting them. The high temperature heat exchangetube 500 may be formed in a cylindrical shape. A first fluid inlet 502,into which the first fluid may be introduced and flow, may project fromthe side wall 508 of an upper portion of the high temperature heatexchange tube 500, and a first fluid outlet 505, through which the firstfluid may be discharged, may project from the sidewall 508, which may bea heat transfer wall, on a lower portion of the high temperature heatexchange tube 500.

Further, an empty space having the same shape as the high temperatureheat exchange tube 500 may be formed therein, and the first fluid inlet502 and first fluid outlet 505 may communicate with the empty space.Accordingly, the first fluid introduced into the high temperature heatexchange tube 500 through the first fluid inlet 502 may flow toward thefirst fluid outlet 505 through the empty space.

The low temperature heat exchange tube 600 may include a low temperatureheat exchange tube portion 610, a connection portion 620, and a secondlow temperature heat exchange tube portion 630. The first lowtemperature heat exchange tube portion 610, the second low temperatureheat exchange tube portion 630, and the connection portion 620 may beformed as one body. The low temperature heat exchange tube 600 may beprovided with the second fluid whose temperature is lower than that ofthe first fluid.

The first low temperature heat exchange tube portion 610 may have adiameter which is smaller than a diameter of the high temperature heatexchange tube 500, and may pass through the high temperature heatexchange tube 500 in a longitudinal direction and be disposed therein.

The first low temperature heat exchange tube portion 610 may be disposedin a center of the high temperature heat exchange tube 500 so that theaxes of the first low temperature heat exchange tube portion 610 and thehigh temperature heat exchange tube 500 are concentric. A second fluidinlet 612, into which the second fluid may be introduced and flow, maybe formed at one end of the first low temperature heat exchange tubeportion 610.

The first low temperature heat exchange tube portion 610 may be in theform of a straight tube formed in a straight line shape in the hightemperature heat exchange tube 500, a bent tube which may be bent atleast once in the high temperature heat exchange tube 500, or a curvedtube which may be curved at least once at a predetermined curvature inthe high temperature heat exchange tube 500.

The connection portion 620 may be a “U”- shaped tube that connects thefirst low temperature heat exchange tube portion 610 and the second lowtemperature heat exchange tube portion 630. Further, the connectionportion 620 may extend from the other end of the first low temperatureheat exchange tube portion 610 opposite the second fluid inlet 612 to abottom of the second low temperature heat exchange tube portion 630.

The second fluid having passed through the first low temperature heatexchange tube portion 610 and the connection portion 620 may flow intothe second low temperature heat exchange tube portion 630. The secondlow temperature heat exchange tube portion 630 may have a diametergreater than a diameter of the high temperature heat exchange tube 600and may be disposed outside of the high temperature heat exchange tube500 to enclose the side wall 508 (a heat transfer surface) of the hightemperature heat exchange tube 500. Axes of the second low temperatureheat exchange tube portion 630 and the high temperature heat exchangetube 500 may be concentric.

The second low temperature heat exchange tube portion 630 may have anupper wall 603, a lower wall 604, and a side wall 608 formed between theupper and lower walls 603, 604 and connecting them. The second lowtemperature heat exchange tube portion 630 may be formed in acylindrical shape. A second fluid outlet 635 may project from an upperportion of the second low temperature heat exchange tube portion 630,from which the second fluid having passed through the first lowtemperature heat exchange tube portion 610, the connection portion 620,and the second low temperature heat exchange tube portion 630 may bedischarged.

Centers of the upper and lower walls 603, 604 of the second lowtemperature heat exchange tube portion 630 may be open so that the hightemperature heat exchange tube 500 may be inserted therethrough, and anempty space may be formed therein whose diameter is greater than adiameter of the high temperature heat exchange tube 500 in the secondlow temperature heat exchange tube portion 630. The empty space maycommunicate with the second fluid outlet 635.

Because the second fluid having flowed into the second heat exchangetube portion 630 is in a state in which its heat has been primarilyexchanged with that of the first fluid in the first heat exchange tubeportion 610, the temperature of the second fluid may be slightly higherthan the temperature of the second fluid when it is introduced into thefirst heat exchange tube portion 610.

FIG. 8 is a sectional view of a heat exchanger according anotherembodiment. Referring to FIG. 8, a heat exchanger 800D may include afirst heat exchange tube 100, into which a first fluid, being theobjective fluid or target, may be introduced and flow, a second heatexchange tube 200, which may be disposed in the first heat exchange tube100 and into which a second fluid may flow, a third heat exchange tube300, into which the second fluid, whose temperature is substantially thesame as a temperature of the fluid introduced into the first heatexchange tube 100, may flow and which encloses an external surface ofthe first heat exchange tube 100, and a connection tube 700 thatconnects the second and third heat exchange tubes 200 and 300 andprovides the second and third heat exchange tubes 200 and 300 with thesecond fluid having the same temperature.

The first heat exchange tube 100 of the heat exchanger 800D shown inFIG. 8 has substantially the same shape and construction as the heatexchangers according to the previous embodiments. Accordingly, likereference numerals have been used to indicate like elements andrepetitive descriptions of the first heat exchange tube 100 have beenomitted.

Referring to FIG. 8, a second heat exchange tube 200 may pass throughthe first heat exchange tube 100 in a longitudinal direction and bedisposed in the first heat exchange tube 100. The second heat exchangetube 200 may be disposed in a center of the first heat exchange tube 100such that the axes of the first heat exchange tube 100 and the secondheat exchange tube 200 may be concentric.

A second fluid outlet 207 may be formed on or at one end of the secondheat exchange tube 200, from which the second fluid having flowed intothe second heat exchange tube 200, may be discharged.

The second heat exchange tube 200 may include have a straight tubeformed in a straight line shape in the first heat exchange tube 100, abent tube which may be bent at least once in the first heat exchangetube 100, or a curved tube which may be curved at least once at apredetermined curvature in the first heat exchange tube 100.

The third heat exchange tube 300 may be disposed outside of the firstheat exchange tube 100 to enclose a side wall 108 of the first heatexchange tube 100. The third heat exchange tube 300 may also be disposedto have concentric axes with the first heat exchange tube 100.

The third heat exchange tube 300 may include an upper wall 303, a lowerwall 304, and a side wall 308 that is formed between the upper and lowerpanels and connecting them. The third heat exchange tube 300 may beformed in a cylindrical shape. A third fluid outlet 307, from which thesecond fluid may be discharged, may project from the side wall 308 on anupper portion of the third heat exchange tube 300. Further, centers ofthe upper and lower walls 303, 304 of the third heat exchange tube 300may be open so that the first heat exchange tube 100 may be insertedinto them, and an empty space may be formed therein whose diameter isgreater than a diameter of the first heat exchange tube 100. The thirdfluid outlet 307 may communicate with the empty space.

The second fluid may flow into the second and third heat exchange tubes200 and 300 so that both tubes 200 and 300 are filled with the sametemperature fluid, and the heat exchanger 800D of this embodiment mayhave a much higher heat exchange efficiency in comparison to prior artheat exchangers.

According to this embodiment, the second and third heat exchange tubes200 and 300 may be formed as one body. Alternatively, the second andthird heat exchange tubes 200 and 300 may communicate with each othervia a connection tube 700. The connection tube 700 may connect thesecond heat exchange tube 200 and third heat exchange tube 300 in orderto provide the second heat exchange tube 200 and third heat exchangetube 300 with the second fluid so that both tubes 200 and 300 are filledwith the same temperature fluid. That is, one end of the connection tube700 may be connected to an end of the second heat exchange tube 200opposite the second fluid outlet 207, and an other end of the connectiontube 400 may be connected to the lower wall 304 of the third heatexchange tube 300.

The second fluid inlet 702 may communicate with a middle portion of theconnection tube 700 so that the second fluid, whose temperature ishigher than that of the first fluid, may flow into the connection tube700.

According to the above detailed description, the heat exchangeraccording to embodiments disclosed herein may have the second and thirdheat exchange tubes disposed inside and outside of the first heatexchange tube into which the first fluid, which may be the objective ortarget fluid, may flow, heat of the second fluid being exchanged withthat of the first fluid, the second fluid flowing into the second andthird heat exchange tubes, so that a heat transfer area of the heattransfer wall on which the first fluid and second fluids contact eachother becomes increased. Then, a heat exchange performance may beincreased compared with a prior art double-pipe heat exchanger havingthe same volume and length.

Embodiments disclosed herein provide a heat exchanger capable ofincreasing a heat exchange performance by increasing a heat transferarea on which first and second fluids contact each other and heatexchange is performed.

Embodiments disclosed herein further provide a heat exchanger that mayinclude a first heat exchange tube that is in a pipe shape, including afirst fluid inlet, into which a first fluid flows, and a first fluidoutlet, through which the first fluid is discharged; a second heatexchange tube that passes through the first heat exchange tube,including a second fluid inlet, into which a second fluid flows, and asecond fluid outlet, through which the second fluid is discharged; and athird heat exchange tube that includes a third fluid inlet, into whichthe second fluid discharged through the second fluid outlet flows again,and a third fluid outlet, through which the second fluid is discharged,the third fluid outlet enclosing an external surface of the first heatexchange tube.

Embodiments disclosed herein provide a heat exchanger that may include ahigh temperature heat exchange tube including a first fluid inlet, intowhich a first fluid flows, and a first fluid outlet, through which thefirst fluid is discharged; and a low temperature heat exchange tubeincluding a first low temperature heat exchange tube having a secondfluid inlet, into which a second fluid flows, and passing through thehigh temperature heat exchange tube, and a second low temperature heatexchange tube that communicates with the first low temperature heatexchange tube, encloses an external surface of the high temperature heatexchange tube and has a second fluid outlet, through which the secondfluid is discharged.

Embodiments disclosed herein further provide a heat exchanger that mayinclude a first heat exchange tube including a first fluid inlet, intowhich a first fluid flows, and a first fluid outlet, through which thefirst fluid is discharged; a second heat exchange tube that passesthrough the first heat exchange tube and into which the second flows,including a second fluid outlet, through which the second fluid isdischarged; and a third heat exchange tube, into which the second fluidflows and which encloses an external surface of the first heat exchangetube and communicates with the second heat exchange tube, including athird fluid outlet, through which the second fluid is discharged,wherein a second fluid inlet tube is included, which is connected to aconnector to connect the second and third heat exchange tubes to providethe second and third heat exchange tubes with the second fluid.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A heat exchanger, comprising: a first heatexchange tube including a first fluid inlet, into which a first fluid isintroduced, and a first fluid outlet, through which the first fluid isdischarged; a second heat exchange tube that passes through the firstheat exchange tube and into which a second fluid is introduced, thesecond heat exchange tube including a second fluid outlet, through whichthe second fluid is discharged; a third heat exchange tube into whichthe second fluid is introduced and which encloses an external surface ofthe first heat exchange tube and communicates with the second heatexchange tube, including a third fluid outlet, through which the secondfluid is discharged; a connection tube that connects the second andthird heat exchange tubes; and a second fluid inlet tube, which isconnected to the connection tube to provide the second and third heatexchange tubes with the second fluid and to allow a moving direction ofthe second fluid in the second heat exchange tube to be the same as thatin the third heat exchange tube.
 2. The heat exchanger according toclaim 1, wherein the second heat exchange tube includes one of astraight tube section disposed in the first heat exchange tube, a benttube section that is bent at least once disposed in the first heatexchange tube, or a curved tube section that is curved at least once ata predetermined curvature disposed in the first heat exchange tube. 3.The heat exchanger according to claim 1, wherein the first fluid has afirst temperature, and the second fluid has a second temperature whichis lower than the first temperature.
 4. A heater comprising the heatexchanger according to claim
 1. 5. A cooler comprising the heatexchanger according to claim
 1. 6. An evaporator comprising the heatexchanger according to claim
 1. 7. A condenser comprising the heatexchanger according to claim 1.